Large-billed Crow

The large-billed crow (Corvus macrorhynchos) is a large and geographically variable Asian crow named for its massive, deep-based and strongly arched bill. Adults are roughly 46–59 cm long, have a wingspan of about 100–130 cm and weigh about 450–1,000 g across the broad species complex, with substantial regional differences in size. The plumage is black, often with a blue, purple or green gloss in good light, and the throat feathers can appear slightly shaggy. The sexes look alike.

In India it is readily separated from the smaller house crow (Corvus splendens) by its entirely dark plumage, much heavier bill and deeper, more guttural voice; the house crow has a contrasting grey neck and upper breast.

The large-billed crow belongs to a taxonomically complex group whose species limits have changed repeatedly as different authorities have split or combined regional forms. AviList v2025b recognises a broad Corvus macrorhynchos rather than treating the Indian Jungle Crow as a separate species.

The form occurring through much of peninsular and central India is generally referred to as culminatus and has often been treated as Corvus culminatus in alternative taxonomies. The birds photographed in central India belong to this Indian form.

Few Asian crows are more ecologically flexible. Large-billed crows occur in forests, wooded mountains, farmland, coastlines, villages and dense cities. They are particularly successful where natural cover is combined with reliable feeding opportunities, including those created by people.

A comparative study published in 2003 from eastern Kyoto City, Japan, found that large-billed crow territories contained more urban land than those of carrion crows (Corvus corone), and that large-billed crows often foraged at garbage stations. Carrion crows used natural or unpaved areas more strongly. The difference shows how closely related species can share the same landscape by using different parts of it.

The large-billed crow is an opportunistic omnivore. It takes insects and other invertebrates, eggs and nestlings, small vertebrates, carrion, fruit, seeds and a wide range of human food waste. It can switch quickly between seasonal natural foods, scavenging and active predation.

A study published in 2003 from Tokyo found both natural and human-derived foods in the diet. Plant material dominated the winter diet, particularly fruits and berries, while food scraps and animal matter were also common. Such flexibility allows the species to exploit short-lived resources and helps explain why it can thrive in both forests and cities.

Social organisation changes with age, season and time of day. Breeding adults usually live as territorial pairs, while non-breeding and younger birds may gather in foraging groups. At night, much larger numbers can assemble at communal roosts.

Vocal communication helps coordinate these shifting social situations. Calls can alert nearby crows to threats or attract others to rich food sources, allowing temporary feeding groups to form quickly even among birds that do not remain together throughout the day.

Like many corvids, large-billed crows show considerable learning ability and social memory. A study published in 2008 of 14 captive birds found stable dominance relationships and showed that individuals adjusted later interactions according to previous encounters. The results support the ability to recognise particular individuals and remember the outcomes of earlier encounters.

The species is not known as a habitual tool user in the wild, but a study published in 2014 showed that trained captive birds could learn to manipulate a hook to retrieve otherwise inaccessible food. The experiment demonstrated flexible problem-solving and visual control of movement without implying that hook use is part of the species' normal wild behaviour.

Large-billed crows form long-term pairs and build substantial stick nests in trees, although artificial structures are also used. Breeding timing varies strongly across the enormous range. A typical clutch contains about three to five blue-green eggs marked with brown. The female performs most or all incubation for roughly 17–19 days, and the male may feed her while she incubates. Both parents later provision the nestlings; classic field studies in Tokyo record young remaining in the nest for about a month before fledging.

Parental care continues after fledging. A study published in 2018 from Shikotan in the Russian Far East followed individually marked young and showed that parents continued caring for them after they had left the nesting territory. Juveniles could remain under parental care until around 90 days of age.

Nests in human-dominated landscapes show how readily the species incorporates novel materials. A three-year study published in 2025 from Salem, Tamil Nadu, India, examined 15 nests and found a mixture of plant, animal-derived and human-made material. About 79% of the recorded material was human-made, with metal wire and galvanised iron strips especially prominent. This flexibility allows birds to use what is locally available, although wire and other hard objects can also create hazards around the nest.

The large-billed crow is classified as least concern on the IUCN Red List. It has an enormous range and remains common in many natural, agricultural and urban landscapes.

State of India's Birds lists the species as a low conservation priority. Its 2025 update estimates a long-term national change of about 8.4% decline, although the long-term trend remains classified as inconclusive. The more recent annual change is estimated at about 1.7% decline per year, which still falls within the assessment's stable category.